GetStringFromRegion
void GetStringFromRegion(BString& string,
fTextBuffer->GetStringFromRegion(str, fSelection.Start(), fSelection.End());
fTextBuffer->GetStringFromRegion(copyStr, fSelection.Start(),
fTextBuffer->GetStringFromRegion(copyStr, fSelection.Start(),
textBuffer->GetStringFromRegion(text, _start, _end);
textBuffer->GetStringFromRegion(text, _start, _end);